Method of making a catch of mechanical switch

The subject of the invention are systems of fastening mechanical fasteners, in particular a method of manufacturing a fastening system with improved structural and strength parameters.

Systems for mechanical fastening are known. Typically, this type of system consists of two main components, a coupling attached to the ground and a second component adapted to it - the coupling surface. The hook surface usually consists of one or more layers of yarn or fibers.

The protruding parts of the fasteners of the mechanical fastening system, usually called hook elements, penetrate the hook surface and engage with the yarn or fibers of the hook surface. The resulting mechanical impact and physical resistance prevent the hook from sliding out of the hook surface until the release forces exceed the peel strength or shear strength of the fastening system.

Experts often require the possibility of selecting or designing fastening parameters for a mechanical fastening system for a particular application of this system. In some applications, the shear strength of the fastening system becomes an important, if not critical, value, so that the designer may demand that the shear strength of the mechanical fastening tabs can be selected to suit the application.

For example, mechanical joint systems can be used in conjunction with interchangeable hygroscopic inserts, e.g., sanitary bands. In US Patent No. 4,846,815 issued on July 11, 1989, Scripps presents a band provided with a fastening device that exhibits resistance to normal shear stress, which is comfortable for the user and does not cause skin irritation. In US Patent No. 4,869,724 issued on September 26, 1989. in the name of Scripps, a joint hygroscopic insert with adhesive tape labels and a mechanical fastening joint are described, used jointly to allow repeated attachment of replaceable hygroscopic inserts by the user and easy replacement of the band after use.

If the mechanical fastening system is used in conjunction with interchangeable hygroscopic inserts, such as hygiene bands, then some minimal shear strength is needed to minimize the risk of mechanical separation during use, to prevent the insert from being detached or even falling out. In this case, there would be a risk of the insole not being absorbed by body secretions that the removable insole is intended to absorb.

If such a replaceable hygroscopic insert is a product used in cases of urinary incontinence in adults, it is preferable to use a mechanical fastening system similar to that described in US Patent Application Publication No. 07/382 157, public No. F40, filed July 18, 1989 on behalf of Gipson et al. However, contrary to the abovementioned requirements of the fastening system providing a certain minimum shear strength, the mechanical fastening system in combination with the adult incontinence insert can only provide some maximum shear strength. This difference is due to the fact that the user may have limited dexterity and strength such that the shear strength turns out to be too great and the user is not able to easily disconnect the replaceable insert to check for soiling or for routine replacement.

In yet another application, it may be desirable to have a mechanical fastening system allowing a certain slip of the fastener relative to the engaging surface in a direction generally parallel to the plane of the engaging surface and in the direction in which fastening engagement is desired. This side slip gives a fastening system that has the ability to reliably adjust the relative positions of the hooks after joining the two parts.

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Other parameters, such as structural or geometrical parameters of the mechanical clamping system, may also be important. Specialists may also require design options for these mounting system parameters. For example, you can choose the amount of protrusion of the side hitch on a value that ensures that the hooks match the specific hitch surface. Another design parameter, the angle between the hitch and the ground, affects the depth of penetration of the hitch into the hitch surface. Thus, the designer may also wish to design this parameter of the geometrical fastening system depending on the number of layers and the strength of the fibers or yarn of the hook surface and the required shear strength of the fastening system.

In particular, it has been found that there is a definite relationship between the angle between the tabs and the ground plane and the shear strength of the fastening system. In addition, there is a relationship between some parameters of the production process and the angles that form the hooks obtained in this process.

Accordingly, the object of the present invention is to provide a convenient method for selecting fastening parameters, in particular shear strength of mechanical fastening fasteners during manufacture of the mechanical fastening system. It is also an object of the present invention to provide a method for adjusting the size of the lateral projections of the mechanical fastening fasteners and the angles that form the mechanical fastening fastening with the ground during the manufacture of the mechanical fastening system. Yet another object of the invention is to provide a mechanical fastening hook having the possibility of lateral slip, parallel to the hooking plane, after tacking and when the mechanical fastening hook and the hooking surface are joined.

The invention includes a joint fastening system of mechanical fasteners for connecting to a respective engaging surface and a method for producing such a fastening fastening system. The set of fastenings of the fastening fastening system consists of a substrate and at least one free-formed fastener, which includes a base, a shaft and a coupling element. The hitch base is attached to the ground, and the shaft is uniform with the base and protrudes from it outside. The catch element is connected to the shaft and sticks out laterally beyond the perimeter of the shaft.

The fixing system can be produced by a method comprising the step of applying a thermosensitive material and a step of heating it to the melting point. A substrate is used to which the heated thermosensitive material can be applied and a means for applying separate portions of this heated thermosensitive material to the substrate.

The substrate is transported in a first direction and at a first speed relative to the means for applying the material. Separate portions of thermosensitive material on the transported substrate are applied in the other direction. The substrate is discharged outside from the application center at an obtuse angle formed by the first and second directions.

In another embodiment, the method of manufacturing the mechanical fastening system increases the shear strength of the mechanical fastening hook. This process includes the steps of transporting heated thermally sensitive material relative to the substrate. Separate portions of the heated thermosensitive material are deposited on the substrate so that there is a positive difference in the speed of the transferred substrate and the deposited heated thermosensitive material.

It is preferable to perform these processes using a print roller provided with a number of cells arranged around its perimeter. The heated thermosensitive material is placed in the cells. The print roller rotates around the longitudinal axis, and the substrate is transported in the first direction and at the first speed in direct contact with the cells. The heat-sensitive material is transferred from the cells to the substrate.

If necessary, the print roller may be provided with a pressure roller to ensure that the nip and nip plane are formed. The substrate is transported by the grip in contact with the cells of the printing roller. The ground is transported from the grip at a given obtuse angle relative to the grip plane. The ground can pass through

168 433 through the grip at a speed that is essentially not equal to the peripheral speed of the print roller.

In the method, in order to increase the shear strength of the mechanical fastening system, the substrate is moved away from the embedding element at a differential speed, i.e. at an obtuse angle. When using the abovementioned shank and roll arrangement, an acute angle is formed between the ground and the shank plane.

Although the description, together with the claims, accurately defines and explicitly reserves the essence of the present invention, its essence will be better understood on the basis of the following description together with the attached drawings, in which the same elements are marked with the same references and:

Figure 1 is a side view of one of the fasteners of the fastening system of the invention

Figure 2 is a schematic side view of a device that can be used to manufacture the fastener for the fastening system of the invention;

Fig. 2 graphically illustrates the result of the impact of the speed difference between the ground being conveyed and the embedding element on the angle of tilt of the latch shaft for two different angles between the ground and the gripping plane;

Figure B is a graph of the influence of the tilt angle of the latch shaft on the shear strength of the mechanical clamping system for two different angles between the ground and the grip plane;

Figure 5 graphically depicts the relationship of both positive and negative speed differences on shear strength of the clamping system for two different angles contained between the ground and the grip plane;

figures 6A and 6B show two catches manufactured according to the present invention at the same positive speed difference between the transported substrate and the printing roller and at different angles between the transported substrate and the grip plane of the device of Fig. 2;

figures 7A and 7B show two catches manufactured according to the present invention at the same positive speed difference between the transported substrate and the printing roller and at different angles between the conveyed web and the grip plane of the device of figure 2;

figures 8A and 8B show two catches manufactured according to the present invention at the same angles between the transported substrate and the grip plane of the device of fig. 2 and with different positive speed differences between the transported substrate and the printing roller; and fig. 9A and 9B show two fasteners manufactured according to the present invention at the same negative speed difference between the transported substrate and the printing roller and different angles between the transported substrate and the grip plane of the device of Fig. 2. .

The fastening system 20 according to the invention comprises at least one hook 22, as shown in Fig. I, and preferably - a hook network 22. Each of the hook 22 of the network can be attached in a given configuration to the substrate 2B. Each of the latches 22 has a base 26, a stem 28 and a coupling member 20. The bases 26 of the latches 22 are in contact, and are connected to the substrate 2B and support the inner ends of the stems 28. The stems 28 protrude outside the substrate 2B and bases 26. The stems 28 have outer ends connected to coupling elements 30.

The coupling members 30 protrude radially sideways from the stems 28 in one or more directions and may resemble hooked spines. As used herein, the lateral term for the hook 22 considered is a direction having a vector component generally parallel to the ground plane 2B. The protrusion of the coupling elements 30 from the circumference of the stem 28 to the side allows the coupling elements 30 to be secured in a suitable engagement surface (not shown). The coupling element 30 is connected and is preferably uniform with the outer end of the hook 22. It is obvious that the element 8

168 433 coupling couplings 30 can be connected to the catches 22 in places between the base 26 and the outer end of the stem 28.

As shown in Fig. 2, the latch network 22 is produced by a suitable device and method comprising methods for obtaining a freely shaped latch 22, as described and claimed below. The term free-form is used to mean a structure that is not removed from the mold or extruder die in a solid form or with a particular shape. Hooks 22 are deposited on the substrate 24 in a molten, liquid state, and are solidified by cooling to a stiff state and, preferably, solidify into the desired structure described below with the desired shape.

The freely shaped latch 22, or latch network 22, can be produced in a production process similar to the process commonly known as gravure printing. When using this process, the substantially flat substrate 24 having opposing flat surfaces is passed through a nip 70 formed by two substantially round rollers, a printing roller 72 and a pressure roller 74, as shown in Figure 2. The axes of the rollers 72 and 74 are essentially parallel, and the rollers are kept in contact with the substrate 24 as it passes through the nip 70. One of the rollers, specifically designated as the printing roller 72, is provided with a network of closed concavities designated as cells 76, corresponding to desired configuration of the catches 22 mounted on the ground 24. A second roller, designated as a pressure roller 74, provides support and response to the print roller 72 in action, ensuring the substrate 24 moves against the roller 72 as the substrate 24 passes through the nip 70.

The thermosensitive material, preferably the thermoplastic material from which the fasteners 22 are formed is supplied from a heated source, e.g. from a gutter 80. The thermosensitive material is heated, preferably, at least to its melting point. The thermosensitive material is introduced into cells 76 as the print roller 72 rotates about an axis. Cells 76 containing the thermosensitive material transport it until it contacts the substrate 24 and transfer the thermosensitive material to the substrate 24 in the desired configuration.

As a result of the relative movement of the substrate 24 and the rollers 72 and 74, the catches 22 are pulled out in a direction showing a lateral component substantially parallel to the plane of the ground 24, forming the shank 28 and the coupling elements 30. Finally, the material of the coupling 22 can be separated from the coupling elements 30 by by means of a separating element 78. However, the separation element 78 can be omitted and separation provided using such manufacturing parameters of the fastening system 20 at which the separation occurs automatically, without the use of special separating elements 78. As a result of the viscoelastic properties of the thermoplastic material, the hook 22 deflects under the influence of gravity and contraction occurring during cooling. The hook 22 is then cooled and, preferably, cooled to form a solid structure provided with a coupling element 30, uniform with the stem 28.

The fastening system 20 is attached to a suitable hook surface. The term hook surface used herein, with which the coupling elements 30 of the fasteners 22 of the fastening system 20 are fastened, refers to a plane or exposed surface with densely spaced holes adapted to the coupling elements 30 and formed by one or more layers of bundles or fibers, or surfaces which is susceptible to local elastic deformations, so that the coupling element 30 can penetrate it unhindered and remain difficult to remove. Holes or local elastic deformations allow the coupling member 30 to enter the plane of the latching surface, wherein the beams (or undeformed material) between the holes (or deformed material) of the latching surface prevent displacement and release of the fastening system 20 until it is intended by the user exceeding the peel or shear strength of the fastening system 20. The hitch surface can be flat or curved.

The hitch surface provided with bundles or fibers is defined as complementary if the holes between the bundles or fibers due to their dimensions

168 433 allow at least one coupling member 30 to pass through the outer plane of the engagement surface, and the beams have dimensions that can engage or otherwise interact with the coupling members 30. The catching surface that is locally deformable is called complementary if at least one of the coupling members is able to cause local damage to the outer plane of the catching surface such that it prevents separation of the fastening system 20 from the catching surface.

A set of suitable hook surfaces includes mesh sponges, knitted fabrics, non-woven materials and needle fabrics.

Returning to Fig. 1, to further elaborate on the components of the fastening system 20 and the individual fasteners 22, it should be noted that the substrate 24 of the fastening system 20 should be sufficiently strong to prevent fiberization between the individual fasteners 22 of the fastening system 20, and should form a surface with which latches 22 clearly engage well, and should allow it to be connected to the attached insert, depending on the wishes of the user. The term connection as used herein refers to the conditions when the first element is attached or connected to the second element either directly or indirectly when the first element is connected to the intermediate element, which in turn is attached to the second element. The assumption is that the connection between the first element and the second element is to last throughout the lifetime of the article.

The ground is an exposed surface to which one or more catches 22 are attached.

Substrate 24 should also be suitable for curling, for use in conventional industrial processes, flexible enough to allow bending of this substrate 24 and its laying in the desired shape, and should be heat resistant from the fasteners 22 deposited on it, without melting. and damage until the claws 22 solidify. Substrate 24 should also be available in a certain width selection. Suitable substrates 24 can be made of knitwear, woven materials, non-woven materials, rubber, vinyl, films, especially polyolefin films and, preferably, thick paper. It has been found to be advantageous to use white thick paper with a basic weight of 0.08 kg / m2².

The base 26 of the latch 22 is generally a flat portion of the latch 22 attached to the ground 24 and is uniform with the outer end of the latch shaft 28. The term base as used herein refers to the portion of the hook 22 that is in direct contact with the ground 24 and supports the shaft of the hook 22. It is not necessary to make a precise distinction between the base 26 and the shaft 28 of the hook 22. It is only important that when using the product, stem 28 separates from base 26 and that base 26 does not separate from substrate 24.

The cross-section of the base 26 should have sufficient structural uniformity, whereby the surface, with the required peel and shear strength of the fastening system 20, resulting from the density of the latch network 22 and the length of the stem 28 of the individual latches 22, provides adequate adhesion to the ground 24. When using a shank 28 of greater length, the base 26 should generally have a larger cross-section to ensure adequate adhesion to the substrate 24 and adequate structural integrity.

The shape of the contour of the base 26 on the substrate 24 is not critical and can be widened in any direction to provide greater structural integrity and thus greater peel strength in this direction. The term outline as used herein refers to the flat contact area of ​​the base 26 with the ground 24. The ratio of the sides of the contour of the base should not be too great, as this could cause instability of the catch 22 when subjected to forces parallel to the shorter side of the contour. A side ratio below approx. 1.5 to 1 and generally a round contour is recommended.

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For the embodiment described below, a base 26 o with a substantially round base shape and a diameter of about 0.76 to 1.27 mm is suitable. If it is desired to manufacture a fastening system with greater peel or shear strength in a particular direction, then the cross-sectional shape of the base 26 can be modified by increasing the geometric dimensions in this direction, so as to increase the strength and structural integrity of the axis perpendicular to that direction. This modification makes the catches 22 stronger when pulled out towards the base 26 reinforcement.

The stem 28 is unitary with the base 26 and projects outwardly of the base 26 and the ground 24. As used herein, the term stem refers to the portion of the hook 22 intermediate between the base 26 and the coupling member 30 and uniform with them. The stem 28 provides the longitudinal offset of the coupling element 30 from the ground 24. The longitudinal term used here means - in the direction having the component outside of the ground 24, when in this direction the perpendicular distance to the ground plane 24 at the base 26 of the latch 22 increases, as opposed to the direction having the vector component directed towards the ground plane 24.

On stem 28 and base 26 of each latch 22 there is an attachment point 26. The anchor point 28 of the stem 28 is a point that can be considered as the center of the base 26 and is usually located within the outline of the base 26. 'The anchor point 26 can be determined by projecting from the side of the latch 22. The side view is a view in a certain radial direction towards the shank 28 and the base 26, which is also parallel to the ground plane 24. If the fastening system 20 is manufactured in accordance with the method described and claimed below, it is advantageous but not necessary if, in order to determine the attachment point 36, the hook 22 is projected in a direction transverse to the ground path through the grip 70.

The transverse distance between the side edges of the base contour 26 is determined for the considered side view, this distance is divided in half, allowing the center 26 to be determined for this view. When dividing the base 26 of the specific side view in half, the slight discontinuities (roundness or roughness created when attached to the ground 24) are ignored. This point is the attachment point 36 of stem 28.

The stem 28 with the ground plane 24 forms the angle α. The term ground plane used refers to the flat surface of the ground 24 at the base 26 of the main hook 22 in question. The angle α is defined as follows: the hook 22 is projected by a profile. The hook profile 22 is one of two specific profiles and is determined as follows. Hook 22 is checked visually when viewed from the direction in which projection 38 is largest. The size of the projection is the distance measured transversely, parallel to the ground plane 24 from the center of the base 26 in this projection, i.e. from the attachment point 36 of the shank 28 towards the most distant attachment point 22 visible in this projection by longitudinally projecting this point down perpendicular to the ground 24 .

It is obvious to the skilled person that the maximum size of the projection 38 is the distance of the outer circumference of the shank 28 or the coupling member 30 to the opposite edge of the base 26. The side view of the latch 22 in which the size of the protrusion 38 is the largest is the profile of this latch 22. It is obvious to the skilled person that if the fastening system 20 is manufactured according to the method described below, the projection 38 has a maximum size in a plane parallel to the machine direction, i.e. that the profile is usually oriented in the transverse direction of the machine. The side view shown in Fig. 1 is one of the hook profiles 22. It is obvious to the skilled person that this profile is a different profile, generally rotated 180 degrees relative to the previously presented profile (so that projection 38 is facing left of the viewer). Each of the two profiles is equally suitable for the method description below.

The attachment point of the stem 28 is determined on the hook profile 22. Then, with the constant holding of the hook 22 in the profile view, a conventional cross-sectional plane 40-40 is carried out, substantially parallel to the ground plane 24, tangentially to the circumference of the hook 22 in its segment located in the largest perpendicular distance from the ground 24. From 168 433 this corresponds to the highest part of the hitch 22. The distance in a perpendicular direction from the conventional cross-sectional plane B0-B0 to the ground surface 2B to which the bases 26 of the latches 22 are attached is the height of the latch 22. The conventional B0-B0 section plane from the highest point is moved down towards the ground 2B, to a height about one quarter less than the maximum height, so that the conventional B0-B0 section plane passes through the catch 22 at a height equal to three-fourth the height measured perpendicularly , from the ground plane 2B to the attachment point 22 most linearly distant from this ground 2B.

The conventional cross-sectional plane B0-B0 is then used to determine three points on the latch 22. The first is the point where the cross-sectional plane intersects the front edge B2 of the latch 22, designated as 75% of the front edge BB. The front edge is the apex of the periphery of the stem 28 extending longitudinally from the ground plane 2B. The second point is at an angle of about 180 degrees to the center of the latch 22 and is the point where the cross-sectional plane BB intersects the rear edge B6 of the latch 22 and is designated as 75% of the rear edge B8. The rear edge is the apex of the periphery of the stem 28 longitudinally protruding towards the ground 2B and is generally located on the opposite side of the front edge B2. The straight line connecting these two points obviously lies in the B0-B0 section plane and is divided in half to determine the center point B7 of the conventional B9-B0 section plane. The angle α which this line forms with the ground plane 2B is the angle of inclination a of the shank 28.

In other words, the angle α which the shank 28 forms with the ground plane 2B is a complement to the 90 degrees of the angle which with a perpendicular to the ground plane forms a straight line connecting the center of the section plane B7 with the attachment point 36. Thus, the angle α of the shank 28 is the smallest angle that said line forms with respect to the ground plane 2B when viewed from different directions of the shank 28, and especially the attachment point 36, this direction being substantially parallel to the ground plane 2B and orthogonal to the perpendicular line this plane. It can be seen that when the latch 22 is viewed approximately in the machine direction or in a direction 180 degrees different from it, the observed angle α of the stem 28 will be about 90 degrees. However, as mentioned above, the angle α to be measured is the angle that is maximally different from the right angle, so in general it is equal to the angle α, measured when the latch 22 is observed from the profile, usually from the direction transverse to the machine direction .

The angle α of the shank 28 relative to the ground plane may generally be equal to the right angle, but it is preferred that the angle between them is sharp, which allows the required strength to be achieved in a particular direction, which is usually parallel to the projection direction of projection 38. So, if the angle α of the shank 28 differs significantly from the right angle, a higher specific shear strength in this direction is obtained. In the described embodiment, the stem 28 arranged at an angle α comprised between 30 and 70 degrees, preferably about 65 degrees, works well. In any case, when the angle 28 of the stem 28 is less than about 80 degrees, the stem 28 is considered to be perpendicular to the ground plane 28 (regardless of lateral orientation).

The diameter B9 of the coupling part is also determined from the profile. This is the maximum diameter of the protuberance near the outer end of the coupling element 30, which is generally perpendicular to the center line direction of the shank 28 and the coupling element 30.

If more precise measurements are required, such determination of the profile, attachment point 36, intersection plane B0-B0 75% of points BB, B7 and B8 and angle α of stem 28 can be advantageously taken by photographing hook 22 and its scaling. If necessary, several photos can be taken to determine the maximum size of the side projection 38 and individual profiles.

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The stem 28 should extend longitudinally from the base 26 at a distance sufficient to place the coupling member 30 at a suitable distance from the ground 24 at a height that allows the coupling member 30 to securely penetrate or engage in the strands of the coupling surface. The relatively long shank 28 has the advantage of being able to penetrate deeper into the engagement surface, which allows the coupling element 30 to interact with more strands or fibers. Conversely, the relatively short length of shank 28 has the advantage that a higher strength hook 22 is obtained, which, however, also has less penetration into the surface of the hook and may therefore not be suitable for use with hook surfaces such as wool or loosely woven needle materials that have a lower packing density for fibers or strands.

If a hitch surface of woven or knitted material is used, it is preferred to use a relatively short shank 28 with a longitudinal dimension of about 0.7 mm, calculated from the ground 24 to a point or part with the largest height of about 0.5 mm. If a full material more than 0.9 mm thick is used as the hooking surface, a relatively long shank 28 with a longitudinal dimension of at least 2.2 mm and preferably at least 2.0 mm is suitable. As the length of shank 28 increases and the shear strength decreases accordingly, the spacing density of the catches 22 of the fastening system 20 can be increased to compensate for this decrease in strength.

As described above, the vertical length of stem 28 determines the vertical distance of the coupling elements 30 from the ground 24. The term vertical distance means the smallest distance measured in a perpendicular direction from the ground plane 24 to the circumference of the coupling element 30. For coupling elements 30 with a fixed geometry, the vertical distance of the elements couplings 30 from the ground 24 as the vertical length of the stem 28 increases. Good penetration, attachment and retention of bundles or fibers through the coupling member 30 of the fastening system 20 are obtained with vertical spacing equal to at least twice the diameter of the bundles or fibers of the coupling surface used, and preferably about ten times the diameter of such fibers or bundles. In the case of the described embodiment, the latch 20 having a vertical spacing of from about 0.2 mm to about 0.8 works well.

The shape of the cross section of the shank 28 is not critical. Thus, stem 28 may have the desired cross-section, corresponding to the above-mentioned parameters relating to the cross-section of base 26. The cross-section is the flat area of ​​any part of the latch 22 defined perpendicular to stem 28 or the coupling element 30. Preferably, stem 28 converges to reducing the cross section as the distance along the shank 28 increases and towards the outside and to the side of the coupling element 30 of the hook 22. This configuration allows a corresponding reduction in the moment of inertia of the stem 28 and the coupling member 30 resulting in a latch 22 exhibiting more constant stresses when applying separating forces to the fastening system 20, thereby reducing the amount of unnecessary material contained in the latch 22.

In order to maintain the desired geometry over a wide range of latch sizes 22, substantially uniform cross-sectional proportions can be used to select the dimensions of the latches 22. One proportion generally determining the convergence of the latch 22 is the ratio of the cross-sectional area of ​​the base 26 to the cross-sectional area of ​​the latch 22 at the highest point of this latch 22. As noted above, the highest point expression refers to a point or part of the shank 28 or coupling member 30 with the largest vertical distance from the ground plane 24. Usually, the latches 22 having a ratio of the base cross-sectional area 26 to the cross-sectional area at the highest point in the range 4: 1 to about 9: 1.

A generally round stem 28, tapering to a base diameter of 26, as discussed above, has been found to be generally suitable for this embodiment, from about 0.66 mm to about 1.27 mm to a diameter at the highest point of about 0.41 up to approx. 168 433 0.51 mm. In particular, a substantially circular cross-section with a diameter of 0.46 mm at the highest point gives a cross-sectional area at this point of about 0.17 mm². A substantially round base cross section 26 with a diameter of 1 mm gives a base cross section of about 0.81 mm /. With this construction, a ratio of the cross-sectional area of ​​the base 26 to the cross-sectional area at the highest point of about 5: 1 is obtained, which is in the said range.

The coupling element 30 is connected to the stem 28 and is preferably uniform with the outer end of the stem 28. The coupling element 30 projects radially outwards and sideways from the periphery of the stem 28 and can also have a vertical vector component oriented vertically, i.e. towards the ground. 24 or outside of it. The term coupling element as used herein refers to any lateral projection relative to the periphery of the stem 28 (as opposed to slight roughness around the periphery of the stem 28), which projection resists separation from the engaging surface. The term circumference means the outer surface of the hook 22. The term radially means - in the direction perpendicular to the ground 24, or from the perpendicular, passing through the attachment point 36 located generally in the center of the outline of the base 26.

In particular, the lateral projection has a component parallel to the ground plane 24 and facing it. It should be noted that both the coupling element 30 and the stem 28 can have lateral and vertical components. It is not important that the sharp end of stem 28 at its outer end may be apparent or that the boundary between stem 28 and coupling element 30 may not be visible at all. It is only necessary that the vertically directed surface of the perimeter 28 is interrupted so that the surface of the coupling element 30 has a component parallel to the plane of the ground 24 and faces it.

The coupling element 30 may have a larger lateral projection 38 than the stem 28, or vice versa. As shown in the drawing, it is advantageous if the coupling element 30 is generally arched and possibly concave. If the coupling member 30 is concave, then this coupling hook 30 comprises a fragment that vertically extends from the base 26, or a sideways position relative to the base 26. This segment is directed sideways towards the shank 28, although it does not need to be directed radially towards the attachment point 36.

The coupling members 30 of each latch 22 in the latch network 22 constituting the fastening system 20 can stand out sideways, in substantially the same direction, if one-way dominant parameters of the fastening system 20, such as peel and shear strength, are desired, they can also be oriented accidentally to provide a substantially isotropic lateral distribution of fastening parameters. The coupling element 30 may have the shape of a hooked, substantially convex spike protruding essentially on one side of the shank 28, which penetrates through the holes of the coupling surface to engage with the coupling surface or the fiber of the coupling surface with a portion near the internal radius of curvature 54 of the coupling element 30. The interaction between the coupling element 30 and the beams or fibers of the coupling surface prevents detachment of the attachment system 20 from the attachment surface until the peeling and shear strength of the attachment system 20 is exceeded. The coupling elements 30 should not protrude too far to the side, otherwise the coupling elements 30 may do not penetrate into the holes of the coupling surface. The cross section of the coupling element should be sized so that it penetrates through the holes of the coupling surface. The cross-sectional area and geometry of the coupling element 30 is not critical as long as the coupling latch 30 exhibits a structural uniformity providing shear and bending strength sufficient to provide the required peel and shear strength of the fastening system 20 comprising a network with a predetermined density of the latches 22. In the described embodiment, hook shaped spike coupling elements 30 with a maximum lateral projection size 38 measured from the center of the base 26 to the outer lateral circumference of from about 0.79 mm to about 1.4 mm are suitable.

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Assuming the use of the latch network 22 in the fastening system 20, this latch network 22 may be of any configuration and density sufficient to achieve the peel and shear strength required for the particular application of the fastening system 20. In general, as the network density increases, the strength increases linearly for peeling and shearing. The individual catches 22 should not be positioned too densely, as this could cause interference in the operation of the coupling members 30 preventing the adjacent catches 22 from engaging with the respective bundles or fibers of the coupling surface. If the catches 22 are densely spaced, there may be clumping, i.e. thickening of the bundles or fibers, closing the openings between these bundles or fibers. Conversely, the fasteners 22 should be spaced infrequently, as this would necessitate the expansion of the substrate 24 to provide the fastening system 20 with adequate peel and shear strength.

It is preferable to arrange the network hooks 22 in rows using a fixed pitch so that each hitch 22 is substantially equidistant from the adjacent hitch 22. In accordance with the manufacturing method described and claimed below, the rows are positioned substantially in the machine direction and transverse to machine direction. In general, each row of catches 22 running along the machine direction as well as row running across the machine's movement should be equidistant from the rows of catches 22 adjacent in the machine's direction of operation, or in the transverse direction, respectively, to ensure a substantially uniform field distribution stresses of the entire fastening system 20 on the coupling surface when exerting peeling forces on the coupling surface. The term pitch refers to the distance measured either in the machine direction or in a transverse direction relative to the machine direction between the centers of the contours of the bases 26 of the latches 22 in adjacent rows. Usually a fastening system 20 provided with a latch network 22 having a pitch in the range from about 1.02 mm to about 5.08 mm in both directions is used, with a pitch of about 2.03 mm being preferred. Preferably, adjacent rows in the transverse direction of the machine are alternately shifted by half a pitch in the transverse direction of the machine relative to adjacent rows in order to double the distance measured in the machine direction between adjacent transverse row catches.

The tabs 22 can be arranged in 1 cm window gratings² comprising a latch network 22 with about 2 to about 10 rows of latches 22 per centimeter, both in machine direction and in the transverse direction, preferably about 5 rows of latches 22 per centimeter in each direction. Such a grid results in a fastening system 20 comprising from about 4 to about 100 catches 22 per square centimeter of substrate 24.

The fasteners 22 of the fastening system 20 may be made of any thermosensitive material that is stable in solid state and retains shape, but is not brittle enough to cause damage when the fastening system 20 is subjected to separation forces. The term thermosensitive used here refers to the properties of the material, which under the action of heat gradually changes from a solid state to a liquid state. Damage is considered to occur when the hook 22 breaks or its strength decreases when the separating forces act on the hook. Preferably, the material has a modulus of elasticity, measured in accordance with ASTM D-638, from about 24,600,000 to about 31,600,000 kg / m2.

In addition, the material of the fastener should have a melting point low enough to allow machining and a relatively high viscosity to ensure visco-viscous consistency at temperatures close to the melting point of the material, so that the shafts 28 can be stretched and the coupling elements 30 easily formed in accordance with the method described below manufacturing. It is also important that the tabs 22 have viscoelastic properties to allow some of the parameters of the structure of the tab 22 to be changed, especially the geometry of the coupling element 30. It is preferred to use a material with a total viscosity of 168 433 ranging from about 20 to about 100 Pascal seconds at the application temperature. 2B.

Viscosity can be measured using a device called Rheometrics Model 800 Mechanical Spectrometer under dynamic operating conditions at a sampling frequency of 10 Hz and material deformation of 10%. It is advantageous to use a system with a disk and a plate, especially with a disk with a radius of 12.5 mm, with a gap between the disk and the plate of about 1.0 mm.

Preferably, the fasteners 22 are made of thermoplastic material. The term thermoplastic refers to non-crosslinked polymers from thermosensitive materials flowing under the influence of heat or pressure. Hot melt adhesives are particularly well suited for the production of the fastening system according to the present invention, especially according to the method described and claimed below. The term hot melt adhesives as used herein refers to viscoelastic plastics that retain residual stress when solidified from a liquid state. Hot melt polyester and polyamide adhesives are particularly useful and recommended. The terms polyester and polyamide as used herein mean the occurrence of chains of repeating ester and, respectively, amide groups.

It has been found that when polyester materials are selected, it is preferred to use a hot melt polyester adhesive with a total viscosity of about 23 ± 2 pascalose seconds at a temperature of about I9B ° C. If polyamide is chosen, it is preferable to use hot melt polyamide glue with a total viscosity of about 90 + 10 Pascal seconds at a temperature of about 20 ° C.

The abovementioned hooks 22 can be manufactured according to a method comprising the steps of applying separate portions of heated thermosensitive material to substrate 2B, which is transported relative to the applied means of applying the heated thermosensitive material. More specifically, the process includes the steps of feeding, for example, the thermosensitive material described above, and heating it to at least the melting point, so that the thermosensitive material is in a molten, fluid state.

Substrate 2B is fed and transported relative to the application center of this heated material. A means of applying separate portions of the heated thermosensitive material is used. The application medium deposits separate portions of the heated thermosensitive material onto the substrate 2B. It is obvious to the skilled person that in order to ensure relative movement of the substrate 2B relative to the application medium, it is possible to cause the application agent to move separate portions of the thermosensitive material while the substrate 2B remains at rest, or, preferably, to cause the substrate 2B to move while the application medium remains at rest.

Two directions are determined when transporting substrate 2B and applying separate portions of the thermosensitive material forming the latches 22. The first direction is the direction of transport of the substrate relative to the application center of the thermosensitive material. The second direction is the direction of application of this material to the transported substrate 2B. The first direction, transport, and second direction, application, form together the angle β.

In order to provide the required shear strength, the preferred and claimed below hook shape 22 is preferably if the angle β is obtuse. In general, the obtuse angle β can be around I00 degrees, with the fastening system 20 achieving relatively high shear strength. It has been found that the value of the recommended angle of about I00 degrees may vary slightly, depending on the means 76 applied for applying the heated thermosensitive material to the substrate 2B.

When carrying out the process of depositing the heated thermosensitive material onto the substrate 2B, it is advantageous if there is a speed difference between the substrate 2B and the applied thermosensitive material. Such a speed difference is considered positive if the speed of substrate 2B in the first direction is greater than the speed, at the point of applying the material to substrate 2B, of any agent, e.g. cells 76 on the printing roller 72, used to apply the heated thermosensitive material to substrate 2B. Conversely, the speed difference is considered negative if, at the place where the thermosensitive material is applied to the substrate 2B, the speed of the transported substrate 2B is lower than the speed of the center 76

161 433 for applying this thermosensitive material. It is obvious to the skilled person that if the center of the heated thermosensitive material remains stationary and the substrate 24 is transported, there is always a positive differential speed. When using a positive speed difference, the rheological viscoelastic properties of the thermosensitive material may result in lateral extrusion of the material and improvement of the desired fastening parameters, especially the desired increase in shear strength.

As can be seen in Figure 2, the fastening system 20 of the present invention can be manufactured using a modified gravure printing process. Methods of intaglio printing are known, for example the method described in U.S. Patent No. 4,643,130 issued February 17, 1988 to the names Sheath et al. and, to illustrate the general state of the art incorporated herein, by reference.

As shown in Fig. 2, the substrate can be passed through a nip 70 formed between two contacting rollers, a printing roller 72 and a pressure roller 74. The rollers 72 and 74 have essentially parallel axes arranged, generally, parallel to the ground plane 24. Each of the rollers 72 and 74 rotates about its axis, so that the rollers 72 and 74 have a substantially common surface in the shank area 70 and in the same direction. If necessary, rollers 72 and 74 may also have substantially equal peripheral speeds at the gripping point.

If desired, both the print roller 72 and the pressure roller 74 may be driven from an external drive source (not shown), or one of these rollers may be driven from an external drive source and the other may be driven by frictional coupling with the first roller. It has been found that an adequate electric motor with an output of around 1500 W can provide adequate driving power. The rotation of rollers 72 and 74 causes the application means to apply the heated thermosensitive material to the substrate 24 to form hooks 22. Rollers 72 and 74 can rotate at the same or at different peripheral speeds. It is only necessary for both rollers 72 and 74 to rotate in the same circumferential direction at point 70.

The application means should allow the temperature of the hook material 22 to be adjusted in a liquid state, provide a substantially uniform pitch spacing of the hook 22 both in the longitudinal direction of the machine and in the transverse direction, and provide the desired density of the hook location 22 over the entire surface. The application elements should also be able to produce taps with different base diameters 26 and different stem heights 28. In particular, the printing roller 72 provides for arranging the catches 22 on the substrate 24 in the form of a suitable network discussed above (or in another configuration) according to the present method of manufacture.

The expression means of application refers to any device transferring loose liquid material of the fastener to the substrate 24 in portions corresponding to individual fasteners 22. The term application means transferring the material of the fastener from the loose state and dispensing this material onto the substrate 24 in portions corresponding to individual fasteners 22.

A suitable means of applying the fastener material to the substrate 24 is a network of one or more cells 76 on the printing roller 72. The term cell used herein refers to any concavity or other part of the printing roller 72 that carries the fastener material from the container to the substrate 24 and deposits this material on substrate 24 in separate portions.

The cross-section of the cell 76 measured on the surface of the printing roller 72 generally corresponds to the shape of the outline of the base 26 of the latch 22. The cross-section of the cell 76 should be approximately equal to the desired cross-section of the base 26. The depth of the cell 76 partly determines the vertical length of the latch 22 and especially the vertical distance from the base 26 to the point or part of the fastener with the highest height. However, if the cell depth 76 exceeds 70% of the diameter of this cell 76, then the vertical dimension of the latch 22 generally remains approximately constant. This is because it is not all contained in cell 76

168 433, the liquid material of the fastener is pulled out of it and applied to the substrate 24. As a result of surface tension and viscosity of the liquid material of the fastener, some of it remains in cell 76 and is not transferred to the substrate 24.

In the described embodiment, it is preferable to use closed, substantially cylindrical cells 76 with a depth of about 50 or about 70% in diameter. If desired, cell 76 may have a slightly tapered shape, similar to a truncated cone, to allow the use of conventional manufacturing processes, e.g., chemical etching.

With a frustoconical configuration, the apex angle of cell 76 should be no greater than about 45 degrees due to the desired convergence of stem 28 and the above-mentioned ratio of base to maximum height. If the convergence of the cell 76 has a larger apex angle, then as a result a hook 22 with too much convergence can be obtained. If the apex angle is too small or the cell 76 is cylindrical, a shank 22 is formed that is substantially uniform over the entire length of the cross-section and as a result has areas of greater stress. In this embodiment, it is preferable to use cell 76 with an apex angle of about 45 degrees, with a diameter measured on the surface of the cylinder of about 0.89 mm to about 1.22 mm, and a depth in the range from 0 to obtain the appropriate hook shape 22. 25 mm to about 0.51 mm.

Print roller 72 and pressure roller 74 should be pressed together along a plane passing through the axes of both rollers to squeeze sticky substance from cells 76 of print roller 72 onto substrate 24, and provide sufficiently strong frictional engagement to drive the mating roller if it does not have external drive. The pressure roller 74 should be slightly softer and more flexible than the print roller 72 to allow pickup material to be received while transferring it to the substrate 24 from the print roller 72. It is preferred to use a pressure roller 74 with a rubber coating of Shore A hardness. of about 40 to about 60.

The temperature of the printing roller 72 is not critical, however, the printing roller 72 should be heated to prevent solidification of the tabs 22 during the process, from transferring from the container to the application on the substrate 24. The surface temperature of the printing roller 72 is generally desirable near the temperature of the material supply container . It has been found to be advantageous to use a printing roll temperature of about 197 ° C.

It should be noted that if a detrimental effect of the hot transferable hook material on the substrate 24 occurs, a cooling roll may be necessary. If a cooling roll is required, it can be integrated into the pressure roll 74 by means known to those skilled in the art. This design often proves necessary when using a polypropylene, polyethylene or other polyolefin substrate 24.

The material used to shape the individual tabs 22 must be stored in a container that maintains the proper temperature for applying the tabs 22 to the substrate 24. Typically, a temperature slightly higher than the melting point of the material is preferred. A material is considered to be at or above the melting point if the material is totally or partly in a liquid state.

If the material in the tank is kept at too high a temperature, it may not have the right viscosity and may result in the production of coupling elements 30 connected sideways to the adjacent couplings 22. If the material temperature is very high, then the couplings 22 may flow from forming small, approximately hemispherical, droplets, with the coupling members not being shaped. Conversely, if the container temperature is too low, material transfer from the container to the application agent may not occur, i.e. it is not possible to properly transfer material from the application agent 76 to substrate 24 in the desired network, i.e. configuration. The material container should also ensure an even temperature distribution of the material in the transverse direction of the machine, be in communication with the means of applying the viscous material on the substrate 24 and allow easy loading of the material or its refilling as it is used.

168 433

A suitable container is the gutter 80 with a length substantially equal to that portion, measured in the transverse direction of the machine, of the printing roll 72 on which the cells 76 adjacent to the gutter are located. The gutter 80 is closed from below at the ends and from the outside. From the top it can be open or closed if necessary. The inner side of the gutter 80 is open allowing free access of the liquid material to the periphery of the printing roller 72, and its penetration into the cells 76, or communication with any other preferred means of applying the thermosensitive material to the substrate 24.

The container is heated from the outside by known means (not shown) to keep the material of the hooks in a liquid state and at a suitable temperature. The recommended temperature is higher than the melting point, but lower than the temperature at which there is a significant loss of viscoelastic properties. If desired, the liquid material inside the gutter 80 can be mixed or recycled to ensure uniformity and uniformity of temperature distribution.

Near the bottom of the gutter 80, a scraper 82 is positioned to regulate the amount of material applied to the print roller 72. The scraper 82 and the gutter 80 are fixed, while the print roller 72 rotates, allowing the scraper 82 to wipe the perimeter of the roller 72 and scrape off material that is not inside cells 76 of cylinder 72, and allows it to be recycled. The design allows the material of the fasteners to be transferred from the cells 76 to the substrate 24 in a predetermined network, according to the geometrical arrangement of the cells 76 around the periphery of the printing roll 72. It is advantageous, as can be seen in Fig. 4, to position the rod 82 in a horizontal plane, in particular in near the most horizontally level position of the print roller located in front of grip point 70.

After applying the latches 22 to the substrate 24, they can be separated from the printing roller 72 and the application means 76. If desired, the separation can be carried out in a separate process step by using the separating means 78 for dividing the latches 22 between the coupling elements 30 of the fastening system 20 and waste. The term waste used herein refers to material separated from the hook 22, not forming part of the fastening system 20. Sometimes, depending on the selection of some parameters, such as the angle γ between the substrate 24 and the application center 76, the speed difference, the viscosity of the heated thermosensitive material, the shape of the cell 76, etc., it may not be necessary to use a separate special separation step. Separation may occur naturally as a result of the action of the substrate 24 transported from the application point.

When using the separating means 78, it can be positioned to adapt to different sizes of the catches 22 and different sizes of the side projections 38 of the coupling elements 30 and ensure uniformity of the entire surface in the transverse direction of the machine. The term separating element refers to any device or part that separates waste from the fastening system at a certain height 20. The term separates refers to the removal operation of the waste from the fastening system described above. The separating means 78 should also be smooth and should not be subject to rust or oxidation, nor should it transfer corrosion products and contaminants (e.g. waste material) to the catches 22. A suitable separation means is wire 78 located substantially parallel to the axis of rollers 72 and 74 and offset from the ground 24 by a distance slightly greater than the vertical distance to the highest point of the solidified hook 22 from the ground 24.

Preferably, the wire 78 is electrically heated to prevent the accumulation of molten material of the fastener on the separation element 78, to regulate the cooling process of the fastener 22 between the moment the material leaves the heated container and the moment of separation, and to provide lateral extension of the coupling elements 30. Heating the separation means 78 should also ensure an even temperature distribution in the transverse direction of the machine so as to obtain a uniform geometry of the entire latch network 22.

Generally, when the material temperature of the taps increases, a lower temperature of the separating agent in the form of a heated wire 78 can be used. Also, when the speed of the substrate 24 drops, the heated wire 78 cools less often at the separation of individual taps from the waste, enabling the use of heated wire 78 with less power at these same temperatures. It is worth noting that as a result of the temperature rise of the heated wire 78, a hook 22 is obtained, in general, a shorter shank 28. Conversely, the length of the shank 28 and the lateral length of the coupling means 30 increase in a ratio inversely proportional to the decrease in the temperature of the heated wire 78. To it is not necessary for the separating means 78 to actually contact the catch 22. Hook 22 can be separated under the action of heat radiated from the separating element 78.

In the described embodiment, it is preferred to use chromium-nickel wire 78 with a round cross-section and a diameter of about 0.51 mm heated to a temperature from about 343 ° C to about 416 ° C. It is clear that instead of the above-described heated wire 78, a knife, laser cutting or other separation means 78 may be used.

It is important that the separating means 78 is positioned so that the material of the hook 22 can be stretched before it is separated from the waste. If the separating means 78 is located too far from the ground plane 24, then the material of the fastener will pass below the separating means 78 and will not come into contact with it forming very long coupling elements 30 located at the wrong distances from the ground 24 or adjacent catches 22. Conversely, if the separating means 78 is positioned too close to the ground plane 24, the separating element 78 will cut off the stems 28 and the coupling elements will not be shaped.

The arrangement of the separating agent with the heated wire 78 according to the manufacturing method described is the position in which it is located approximately in the longitudinal direction of the machine, a distance of about 14 to 22 mm, preferably about 18 mm from grip point 70, at a distance of about 4 , 8 mm to 7.9 mm in the radial direction from the pressure roll 74 and at a distance of about 1.5 mm to about 4.8 mm in the radial direction outside of the print roller 72.

During operation, the substrate 24 is transported in a first direction relative to the application means 76. More specifically, the substrate 24 is transported by a shank 70 and, preferably, pulled away by a take-up roller (not shown). This results in continuous feeding of the clean surface of the substrate 24 for continuous deposition of the catches 22, and removal of a portion of the substrate 24 with the catches 22 already applied thereto. The direction, generally parallel to the main direction of transport of the substrate 24 when it passes through the grip 70 is called the machine's direction of operation. The machine operating direction, as shown by arrow 75 in Fig. 2, is substantially perpendicular to the axis of the printing roller 72 and the pressure roller 74. The direction, generally perpendicular to the machine operating direction and parallel to the ground plane 24 is called the transverse direction of the machine. The shank plane is a plane having an edge common with the shank and tangent to the print roller 72 and the pressure roller 74.

After transferring the hook material from cell 76 to the substrate 24, rollers 72 and 74 continue to rotate in the directions indicated by arrows 75 in Fig. 2. This causes relative movement of the transported substrate relative to cells 76 when the material of the hook 24 of the substrate 24 is present at that time. 72. As this movement proceeds, the material of the seams is stretched until separation and detachment of the seams 22 from cells 76 of the print roller 72 occur. As used herein, the term tension means an elongation, at least some of which remains permanently, for the entire useful life of the fastening system 20.

As discussed above, it may be necessary to introduce the separation of individual tabs 22 from the printing roller 72 as a step in the method of shaping the coupling members 30. During separation, the tab 22 is split in length into two parts, at the outer end with the coupling element 30 that remain in the system 20 and waste (not shown) which remains at the printing roller 72 and can be recycled to the process if required. After separating the catches 22 from the waste, the fastening system 20 has the ability to solidify before the catches 22 come into contact with other objects.

161 433

After the hooks 22 are solidified, the substrate 24 may be wound onto a roll if necessary for storage.

The substrate 24 can be transported through the grip 70 in the first direction at a speed of about 3 to about 31 m / sec. The substrate 24 can be drawn through the nip 70 at a speed of approximately 25% greater to about 15% lower than the circumferential speed of the print roller 72 resulting in a difference in speed from positive 25% to negative 15%. A positive speed difference of at least 2% is preferred. Thus, if the device of Fig. 2, the speed of transported substrate 24 is at least 2% greater than the peripheral speed of the printing roller 72.

The fastening parameters, in particular shear strength, of the fastening system 20 or of the single hook 22 can be changed by changing the angle β between the two directions resulting from the dynamic stages of the present method, the first direction being essentially the direction of transporting the substrate 24 and the second direction in which the heated thermosensitive material is applied to the transported substrate 24. The specific angle γ is created by using a device in which, as an application agent 86, a printing roller 72, a pressure roller 74 and a shank 70 are used to apply the heated thermosensitive material to the transported substrate 24. It is obvious to the skilled person that when using this device for applying the heated thermosensitive material to the substrate 24 during application, the angle γ will be approximately 90 degrees, since the first direction of transporting the substrate 24 through the shank 70 is generally orthogonal to the second direction in which the heated thermosensitive material is withdrawn from cell 76 on the periphery of the printing roll 72.

As noted above, the substrate 24 can be pulled sideways from the grip plane 70 of the print roller 72 at a certain angle y that is sharp relative to the grip plane 70 and obtuse with respect to the application direction of the heated thermosensitive material on the transported substrate 24. Typically, if the angle γ (between the direction of web transport after leaving the grip 70 and the grip plane 70 or more generally, the angle (1 between the first direction of transporting the substrate 24 and the second direction of applying the heated thermosensitive material to the transported substrate 24), a securing system 20 o higher shear strength as shown in the following figures and discussed in more detail in the description below.

This relationship is valid regardless of the relative speed difference between transported substrate 24 and the means 76 for applying heated thermo-sensitive material to the transported substrate 24. This relationship is also valid for both positive and negative speed difference. It is preferable to use a method in which the transported substrate 24 is pulled at an obtuse angle β relative to the application direction of the heated thermosensitive material on the transported substrate of about 100 degrees to about 110 degrees, or more if the transported substrate 24 is pulled sideways from the grip plane 70 at an angle γ of about 5 to about 40 degrees.

From Fig. 3 it can be seen that, in general, if the positive speed difference increases, the angle α of the catches 22 relative to the ground 24 decreases, i.e. that the catches 22 become more protruding to the side and closer to parallel to the ground plane 24. This relationship is important and essentially linear for the two selected y angles of 15 degrees and 35 degrees between the grip plane 70 and the line along which the substrate 24 is pulled away from the grip 70, and covers the range from a negative, 11%, speed difference to positive, of 16% speed difference.

Fig. 4 shows the shear strength of a sample of the mechanical clamping system 20, measured in grams of force applied to a sample of the clamping system 20 with an area of ​​about 4.84 cm². This sample size was chosen because it is large enough to obtain a representative sample test result and has typical application sizes. Shear force can be measured when stretching the hooked fastening system 20 and the hook surface in opposite directions, substantially parallel to the ground plane 2B and the plane of the hook surface. During the measurement, the angle of inclination of the hook 22 is generally facing in the same direction in which the ground stretching machine 2B is pulled (the hook 22 of Fig. I is pulled to the right). The method used to determine the shear strength of the clamping system 20 is more fully described in U.S. Patent No. B 699 622 issued to IB October I987. in the name of Toussand et al., which is incorporated by reference to this description to explain the appropriate technique for measuring shear forces.

It can be seen from Fig. B that the shear strength of the fastening system 20 depends on the angle α of the slope stems 28 of the latches 22, and thus on the speed difference, via the relationship shown in Fig. 3. It is preferred if the angle and between stems 28 and substrate 2B is less than about 70 degrees, and preferably less than about 65 degrees, which allows a shear resistance of at least about I000 G / B, 8 cm to be obtained² because, as you can see, shear strength decreases rapidly when the angle of inclination to the ground exceeds 65 to 70 degrees. Also from Figure B, it follows that for all readings of the angles of inclination of the shafts a and greater shear strength are obtained when pulling the substrate 2B away from the grip plane 70 at an angle γ equal to I5 degrees than at an angle γ greater than 35 degrees.

From Figure B it is generally seen that it is desirable to select an angle a between the shank 28 of the latch 22 and a substrate 2B smaller than 70 degrees. In particular, an angle? Of from about 20 degrees to about 65 degrees is preferred. This relationship is also valid for both angles γ between the grip plane 70 and the line through which the ground is pulled back after leaving the grip 70.

Figure 5 shows the relationship between the difference in speed of the transported web 2B and the shear strength of the mechanical fastening system 20 produced at such a speed difference. The figure includes both positive and negative speed differences. However, it is generally clear from Figure 5 that a positive speed difference of about 2% to about I6% is desired. This relationship remains valid for both claimed angles γ between the grip plane 70 and the line through which the transported substrate 2B is pulled back after leaving the grip 70.

Another factor that is considered by specialists is the radius of curvature of the print roller 72 and its effect on the speed and angle differences y between the substrate 2B and the gripping plane 70. As the radius of curvature of the print roller 72 decreases, the shank 28 of the latch 22 is formed, along with with waste, it is pulled away from the ground 2B at an angle relative to the grip plane 70, which near the grip 70 is almost straight. After solidification, such a hook 22 typically has a larger angle of inclination a than a hook 22 produced under similar conditions, but with a larger radius of curvature of the print roller 72.

Thus, to avoid a decrease in shear strength, based on the relationship of Fig. B, when the radius of curvature of the printing roller 72 decreases, either the speed difference and the angle y between the transported substrate 2B and the grip plane 70, or both, should be reduced. If the radius of curvature of the print roller 72 increases or decreases, without appropriate compensation for the speed difference or angle γ, the angle of the hook 22 and thus the shear strength of the fixing system 20 may not reach the value of the application required. Especially if the difference in speed and angle y are not matched to the radius of curvature of the printing roller 72, then the waste of the latch 22 may be directed too orthogonally to the substrate 2B and, after solidification, the latch angle 22 will be greater than desired resulting in less than the required strength of the fixing system 20 shear. Thus, in order to obtain the improved fastening system 20 according to the present invention, it is important to provide in the device for producing the fastening means a means of imparting vector orientation of separate portions of applied thermosensitive material which is not orthogonal (above about 10 degrees in both directions from the axis) relative to

168 433 ground planes 24 at the base 26 of the latch 22. When using the device of Fig. 2, the two means to impart a non-orthogonal vector orientation of the substrate 24 relative to separate portions of thermosensitive material are: said speed difference and the sharp angle γ between grip plane 70 and conveyed substrate 24.

Numerous modifications to the device and method of the invention are possible without departing from its scope. If necessary, using a relatively strong substrate 24 and sufficient tension, the pressure roller 74 may be omitted from the device of Figure 2. Instead, as is known to those skilled in the art, substrate 24 may circulate the print roller 72 by using guide rollers that create around S-loop print roller In this configuration, there is no grip 70 shown in Fig. 2, instead, the transfer of the heated thermosensitive material from the cells 76 of the print roller 72 ensures the tension of the substrate 24. It should be noted, however, that with this variant of shaping the means for applying the heated thermosensitive material to the substrate 24, the substrate 24 must have sufficient tensile strength to avoid breaking and provide the stress necessary for the correct application of the heated thermosensitive material.

The following are four illustrative, non-limiting examples of joining, changing, determining, and using various parameters to produce a fastening fastener system 20 with the desired structure, geometry, and shear strength. Figures 6A to 9B show the fasteners 22 of the fastening system of each example.

Assuming initially parameters that remain constant for all four examples, it is assumed that the material used is Bostik 7199 polyester hot melt adhesive. The adhesive is maintained at a temperature of about 179 ° C to 181 ° C. The adhesive is applied to a substrate of bleached cellulose paper 24 with a thickness of 0.13 mm to 0.18 mm transported at a constant speed of about 6.31 m / min.

The device selected for applying the heated thermosensitive material is similar to the device of Fig. 2 and is provided with a printing roller 72 with a diameter of approximately 17 cm and a support roller with a diameter of approximately 15.2 cm. The printing roller is equipped with a network of closed cells 76 in the shape of a truncated cone, each with a diameter of 1.0 mm, located on the circumference of the printing roller 72, having a depth of 0.46 mm and arranged in a network with a density of about 75 cells / cm2

In each example, separation means 78 are used, in particular heated wire 78 with a diameter of 0.76 mm and a length of about 61 cm. In each example, the heated wire 78 is positioned horizontally about 5.1 mm from the printing roll 72 and about 22.9 mm from the support roll 74. The wire 78 is electrically heated.

Among the parameters that change in the examples are the electrical power supplied to the heated wire 78, controlled depending on the distance of the heated wire 78 from the ground 24 and the speed of the printing roll 72 to take into account the cooling occurring during the interaction between the circuit of the heated wire 78 and the surfaces of the taps 22 made according to individual examples. The angle β between the application agent 76 and the substrate 24 is changed to show the effect of two different angles β. In particular, the examples use γ angles between transport substrate 24 and grip plane 70 of 15 degrees and 35 degrees.

The speed difference between the application means 76 and the transported substrate 24 is also changed, taking into account both the positive and negative speed differences. In each example, either the speed difference is kept constant and the angle γ is adjusted, or vice versa, so that in one example both parameters never change.

Example I. The fastener 22 of FIG. 6A shown in FIGS. 6A and 6B is manufactured in accordance with the parameters of Table IA, and the fastener 22 of FIG. 6B is manufactured in accordance with the parameters of Table IB. Both catches are produced at the same speed difference of 2%, and the angle y between the grip plane 70 and the transported substrate 24 changes from an acute angle of 15 degrees to an acute angle of 35 degrees. Other parameters used in the method of manufacturing the fasteners of Fig. 6A and 6B are the same.

168 433

It can be seen from the bottom of Table IA and IB that, according to Figs. 4 and 5, the hook 22 having a slope angle γ 15 degrees gives a shear strength of almost 35% greater than the hook 22 in Fig. 6B, with a slope angle γ of 35 degrees. However, the hook 22 of Fig. 6B is almost 25% narrower and has a smaller lateral projection.

<td></td><td>Table IA</td><td>Table IB</td>

<td>WORKING PARAMETERS</td><td></td><td></td>

<td>Speed ​​difference</td><td> +2%</td><td> +2%</td>

<td>The angle γ between the web and the grip plane</td><td> 15°</td><td> 35°</td>

<td>Power of heated wire (watts)</td><td> 95,2</td><td> 95,2</td>

<td>HITCH PARAMETERS</td><td></td><td></td>

<td>Shear strength (G / 4.8 cm²)</td><td> 6 600</td><td> 5 100</td>

<td>Inclination angle α</td><td> 66°</td><td> 60°</td>

<td>Maximum lateral projection</td><td> 2,14</td><td> 1,45</td>

<td>Height</td><td> 2,23</td><td> 2,78</td>

<td>Diameter of the coupling element</td><td> 6</td><td> 7</td>

Example II Figs. 7A and 7B show the tabs manufactured using the parameters of the tables, ILA and IIB, respectively, regarding the tabs obtained at a positive speed difference of 6.6%, but with a change in the angle y between the plane of grip 70 and the direction of transporting the substrate 24 with about 15 degrees to about 35 degrees. The coupling element 30 of the latch 22 of Fig. 7B has a significant slope inward towards the anchor point 36 of the base 26. However, similarly to Fig. 4 and the hook 22 of Fig. 7A has a shear strength greater by about 7% than the hook 22 of Fig. 7B. The explanation for the increase in shear strength of the latch 22 of Fig. 7 is that the inward direction of the coupling member 30 allows the greater number of fibers of the hook surface cooperating with the fastening system 20 to be hooked, and the non-hooked fibers do not contribute to a significant increase in shear strength.

<td></td><td>ELA board</td><td>Table IIB</td>

<td>WORKING PARAMETERS</td><td></td><td></td>

<td>Speed ​​difference</td><td> +6,6%</td><td> +6,6%</td>

<td>The angle γ between the web and the grip plane</td><td> 15°</td><td> 35°</td>

<td>Power of heated wire (watts)</td><td> 80,0</td><td> 95,2</td>

<td>HITCH PARAMETERS</td><td></td><td></td>

<td>Shear strength (G / 4.8 cm²)</td><td> 5 900</td><td> 5 500</td>

<td>Inclination angle α</td><td> 55°</td><td> 58°</td>

<td>Maximum lateral projection</td><td> 1,94</td><td> 2,28</td>

<td>Height</td><td> 2,24</td><td> 2,45</td>

<td>Diameter of the coupling element</td><td> 6</td><td> 5</td>

Example III. In Example III, the speed difference varies when receiving the tabs 22, each having the same angle γ between the grip plane 70 and the plane of the transported substrate 24. The same angle γ for both catches 22 of Figures 8A and 8B is about 35 degrees. For the latch 22 of Fig. 8A, the speed difference is positive and is about 16%, while the latch of Fig. 8B is the latch 22 of Fig. 6B for a positive speed difference of 2%. It is obvious to those skilled in the art that the coupling member 30 of the hook 22 of Figure 8A has a very large side projection size 38, nearly 71% larger than the hook of Figure 8B. Hitch 22 of Fig. 8A has a large lateral projection 38 that the hitch 22 can slide in the lateral direction parallel to the ground plane 24 after it is seen with the hitch surface, provided, of course, that this slip occurs substantially along the direction of the hitch profile 22. Hook 22 of Fig. 8A has a shear strength of even about 10% greater than the fastener of Fig. 8B. This result is consistent with the relationships shown in Figures 3.4 and 5. With the difference increasing

161 433, the angle of inclination cc decreases, according to Fig. 3, and therefore the shear strength increases according to Fig. 4. Also as the speed difference increases, the corresponding shear strength increases according to Fig. 5.

<td></td><td>Table IIIA</td><td>Table IIIB</td>

<td>WORKING PARAMETERS</td><td></td><td></td>

<td>Speed ​​difference</td><td> +16%</td><td> +2%</td>

<td>The angle γ between the web and the grip plane</td><td> 35°</td><td> 35°</td>

<td>Power of heated wire (watts)</td><td> 128</td><td> 95,2</td>

<td>HITCH PARAMETERS</td><td></td><td></td>

<td>Shear strength (G / 4.8 cm²)</td><td> 5 600</td><td> 5 100</td>

<td>Inclination angle α</td><td> 45°</td><td> 60°</td>

<td>Maximum lateral projection</td><td> 4,15</td><td> 1,45</td>

<td>Height</td><td> 1,97</td><td> 2,78</td>

<td>Diameter of the coupling element</td><td> 3</td><td> 7</td>

Comparing the results from examples I and ΙΠ it should be noted that both the highest and the lowest shear strength occurred in the case of the fastener 22 from example I with a positive speed difference of 2%. This difference in shear strength indicates that, with a slight positive speed difference, the manufacturing process is more sensitive to changes in the angle of inclination γ between substrate 24 and grip plane 70.

Example IV. Each of the fasteners 22 shown in FIGS. 9A and 9B manufactured according to the parameters of these figures exhibits a negative speed difference of 11% and reduced shear strength compared to the fasteners 22 of the previous examples. However, according to Figs. 4 and 5, the latch 22 of Fig. 9 A, having an angle γ between the transported substrate 24 and a grip plane 70 of 15 degrees, shows almost 27% greater shear strength than the latch of Fig. 9B having an angle γ between the transported substrate 24 and a grip plane 70 of 35 degrees.

<td></td><td>Table IVA</td><td>Table IVB</td>

<td>WORKING PARAMETERS</td><td></td><td></td>

<td>Speed ​​difference</td><td> 11%</td><td> 11%</td>

<td>The angle y between the web and the grip plane</td><td> 15°</td><td> 35°</td>

<td>Power of heated wire (watts)</td><td> 80,0</td><td> 80,0</td>

<td>HITCH PARAMETERS</td><td></td><td></td>

<td>Shear strength (G / 4.8 cm²)</td><td> 3 300</td><td> 2 600</td>

<td>Inclination angle α</td><td> 87°</td><td> 86°</td>

<td>Maximum lateral projection</td><td> 1,85</td><td> 2,05</td>

<td>Height</td><td> 2,46</td><td> 2,52</td>

<td>Diameter of the coupling element</td><td> 6</td><td> 5</td>

It is obvious to the skilled person that other modifications and combinations of the parameters described above are also possible. For example, many parameters can be adjusted, including the temperature of the heated wire 78, its placement, other speed differences, and various means of applying the heated thermosensitive material to the transported web 24. All these combinations and combinations fall within the scope of the following claims.

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